Copyright © 2006 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
Mark C. Gebhardt, MD*,
Beth Israel Deaconess Medical Center, Boston, Massachusetts
Forty years ago, a child with a malignant bone tumor such as osteosarcoma or Ewing sarcoma would have about a 10% chance of survival and most would lose a limb in an attempt to gain at least local control1. Advances in adjuvant chemotherapy have dramatically improved the outcomes associated with both of these tumors, and survival rates of 70% to 80% or more have been achieved2,3. Along with these advances, orthopaedic surgeons have developed techniques to salvage limbs and avoid amputation in adults and children. Although there are no randomized studies, the retrospective data suggest that limb salvage is safe, with local recurrence rates similar to those seen after amputation4. Less clear are the long-term functional quality-of-life outcomes, and in skeletally immature children5, there is the added concern of limb-length discrepancy.
Futani and colleagues have addressed the issues of limb salvage in skeletally immature patients at a single site, the distal end of the femur, in a retrospective questionnaire study of forty children who were eleven years of age or less at the time of diagnosis. The major strength of this contribution is that very few authors have limited the study of limb salvage to a solely skeletally immature population. Since the distal femoral growth plate was resected in all of these patients, the issue of limb length as well as the functional results and complications could be addressed. They also compared endoprostheses (twenty-eight patients) to "biologic" reconstructions (twelve patients). Employing the Musculoskeletal Tumor Society functional evaluation, the functional scores in each group were similar (74% ± 18% in the endoprosthetic reconstruction group and 68% ± 17% in the biologic reconstruction group; p = 0.3672). Nineteen patients underwent limb-lengthening, and those who had this procedure had improvement in the functional score (81% ± 11% versus 65% ± 21% before lengthening; p = 0.0016). Interestingly, 42% of the patients did not undergo a lengthening and eight of the thirty-three patients chose not to have a lengthening. Despite lengthening, fifteen of nineteen patients had a final limb-length discrepancy of 2 cm or more. Overall, the mean discrepancy was 5.5 cm (2 to 15 cm) at skeletal maturity. Endoprostheses were associated with deep infection (27%) and aseptic loosening (23%), whereas implant breakage and nonunion were more frequent in the biologic reconstruction group. Seventeen patients required a revision of the original reconstruction. Five of the thirty-three patients who survived ten years or more required amputation for complications, and the limb salvage rate at ten years was 51% for endoprostheses and 46% for the biologic group.
This study is limited in that it is retrospective and is a multicenter questionnaire study. The authors excluded patients who had amputation or rotationplasty, which might have yielded interesting quality-of-life comparisons. The functional analysis presents the observations of the surgeons but not the patients, and no true assessment of the patient's quality of life is presented. The endoprostheses are similar to those employed in the United States and the United Kingdom, although I suspect that in these countries patients would have had a higher rate of expandable prostheses than the seven of twenty-eight used in this study. The biologic reconstructions were not similar to those routinely employed by most centers in the United States. Arthrodeses are now seldom employed, and the intercalary resections that were performed made use of distraction osteogenesis or a vascularized fibular graft to reconstitute the bone defect. No osteoarticular grafts were employed. They also did not use other techniques of limb equalization, such as epiphysiodesis or closed femoral shortening, that are routinely used in pediatric surgery.
We have made dramatic improvements in the ability to salvage limbs with a low local recurrence rate, but our methods of reconstruction leave much to be desired. The techniques we employ are associated with many complications, and limb-length discrepancy in children adds a further problem not encountered in adults. However, this particular issue is relatively easy to address, even if a simple shoe lift is employed. Of more concern is the long-term survival of the reconstructions over twenty or more years. These patients may live for many years, and the reconstruction challenges as they grow older and the implants fail or loosen will pose difficult challenges for the patient and the surgeon.
In this report at ten years, 74% of the patients experienced a complication and only half of the index reconstructions survived to ten years. We need better implants and, ideally, tissue-engineering approaches to these problems if we are really to solve this complicated reconstruction challenge. In the meantime, this study shows that limb length discrepancy is an important issue and that equalizing limb lengths provides a functional benefit to the patient. It would be useful to know whether the patient's acceptance of these procedures mirrors the acceptance rate of the surgeons, and how many patients will ultimately require amputation in the future. We cannot conclude that limb salvage offers superior function and outcomes compared with these complicated limb reconstructions. The reported results suggest little difference5. Have we really improved the quality of life of patients with sarcoma by offering them limb salvage? Would we reach different conclusions about the optimal management of the primary tumor if the patients who had rotationplasty or amputation were included? What will happen to these patients with endoprostheses and arthrodeses in twenty years, thirty years, and fifty years? We have made major advances in the care of these children, but we have a long way to go before we can say we have made the same advances as our colleagues in the field of pediatric oncology.
*The author did not receive grants or outside funding in support of his research for or preparation of this manuscript. He did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. A commercial entity (Stryker Foundation) funds an oncology fellow at the Massachusetts General Hospital who rotates through Dr. Gebhardt's institution.
References
1. Link MP, Goorin AM, Miser AW, Green AA, Pratt CB, Belasco JB, Pritchard J, Malpas JS, Baker AR, Kirkpatrick JA, Ayala AG, Shuster JJ, Abelson HT, Simone JV, Vietti TJ. The effect of adjuvant chemotherapy on relapse-free survival in patients with osteosarcoma of the extremity. N Engl J Med. 1986;314:1600-6.
2. Goorin AM, Schwartzentruber DJ, Devidas M, Gebhardt MC, Ayala AG, Harris MB, Helman LJ, Grier HE, Link MP; Pediatric Oncology Group. Presurgical chemotherapy compared with immediate surgery and adjuvant chemotherapy for nonmetastatic osteosarcoma: Pediatric Oncology Group Study POG-8651. J Clin Oncol. 2003;21:1574-80.
3. Grier HE, Krailo MD, Tarbell NJ, Link MP, Fryer CJ, Pritchard DJ, Gebhardt MC, Dickman PS, Perlman EJ, Meyers PA, Donaldson SS, Moore S, Rausen AR, Vietti TJ, Miser JS. Addition of ifosfamide and etoposide to standard chemotherapy for Ewing's sarcoma and primitive neuroectodermal tumor of bone. N Engl J Med. 2003;348:694-701.
4. Simon MA, Aschliman MA, Thomas N, Mankin HJ. Limb-salvage treatment versus amputation for osteosarcoma of the distal end of the femur. J Bone Joint Surg Am. 2005;87:2822.
5. Nagarajan, R, Clohisy, DR, Neglia, JP, Yasui, Y, Mitby, PA, Sklar, C, Finklestein, JZ, Greenberg, M, Reaman, GH, Zeltzer, L, Robison LL. Function and quality-of-life of survivors of pelvic and lower extremity osteosarcoma and Ewing's sarcoma: the Childhood Cancer Survivor Study. Br J Cancer. 2004;91:1858-65.
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